Mini-Bobcat flew today - RC Groups
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Jul 24, 2002, 03:38 PM
EDF all the way!
bruff's Avatar

Mini-Bobcat flew today

Flew my new Mini-BobCat today. All I can say is Wow! It uses the WeMoTec Mini fan with a Astro 805 power system on 10 cells (Sanyo 4/5 AUP 1700 ma cells. This plane is quick.With the above batteries I'm using 250 Watts which produces 31,000 RPM. Flying weight is 39 oz. I'll be doing more test flights next Sat. Keep you posted.
Thanks, dcronkhite for the plans!

Here is another picture.
Last edited by bruff; Jul 24, 2002 at 03:42 PM.
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Jul 24, 2002, 04:19 PM
Col.Hooligan Air Force
uncljoe's Avatar
Looks real sharpe ,could it employ retracs?

Semper Fi
Jul 24, 2002, 04:26 PM
Flying Welder Pilot
Plane Crazy's Avatar

Bobcat,Bobcat, Bobcat, Bobcat........

Very COOL Bob , Fixed gear and all. ROG?
What did you use for control throws? I guess I'll have to dust off dcronkhite's plans and knock one out. I have a spare 805 and a minifan kicking around the shop looking for a home.

I imagine Bob Violett will be seeing some of these mini Bobcat EDFs flying around some jet meets.

Keep us informed on the flight tests

Last edited by Plane Crazy; Jul 24, 2002 at 04:29 PM.
Jul 24, 2002, 05:35 PM
Tim H.'s Avatar
Great job Bob! I've been wanting to do the Mini Bobcat for a while, but I have so many other projects going that I just can't get one more going right now. It is definately on the to-do list though.

How did the Sanyo 4/5 AUP 1700 ma cells do? What was your run time. Same power as the CP1700s? I've been watching to see how these new cells are doing. 10 of these puppies are almost 6oz. lighter than 10 CP1700s. Might help the power to weight ratio a bit I'd say.

I was thinking of using 12 of those cells and a Mega 16/15/3 in a MF480. Chris True tested the little mega 16/15/3 on 12 CP-1300's. It was just over 34K @ about 350 watts with the current draw 23-24 amps. That would put it at 145 watts per pound at 39 oz. Woooo Whoooo. Here is the thread with the info.

Tim H.
Jul 24, 2002, 07:04 PM
EDF rules... :)
AirX's Avatar

Way to go!!!

Hi Bob,

The plane looks great. How did you do the wing, built up balsa are did you cut foam. I was ondering how you did the sub fuses concerning the wing. Doug was turning over the idea of plug in outer panels.

Jul 24, 2002, 07:20 PM
EDF all the way!
bruff's Avatar


Thanks Guys, the plane is fixed gear. Take offs are ROG. The wing is foam, two halves glued together. Has four servo's, two for the ailerons, one for the elevator and one for the nose steering. I think the Mico EJF retracts may fit. The cells seem to be doing fine, I need to compare numbers to a Nicad pack to see how they are. Next week I will finish covering it. Did enough so I could get the flight in.
Jul 24, 2002, 07:30 PM
Registered User
Ed Waldrep's Avatar
Steve Neu's "Power On" column in the new (Sept issue) S&E Modeler has a discharge graph of the 4/5 AUP 1700 cells at 10 and 20 amps and they seem to hold voltage pretty well, over 1 volt for 3/4 of the run, right before the steep drop in voltage near the end. No tests at 30 amps but Steve said that he thought that they'd hold up well, and they like to be run hot off the charger, voltage drops if they are allowed to cool after charging. They sound promising.
Jul 24, 2002, 11:18 PM
Ductedfann's Avatar

mini bob

That looks cool
Jul 25, 2002, 04:50 PM
Registered User
kevin's Avatar
just sent an email to doug, hope he's listening

looks like i might have found a new home for my hacker b40-12s.
retracts would be a must.

did you cut your own cores?
Jul 25, 2002, 06:27 PM
Doug Cronkhite's Avatar
I'm still here.. Just have been focused on other priorities lately in the 'real world'. Hope to get back to work on the updated Mini-Bobcat in the future.. but I wouldn't count on it for at least 3 months.

My goal is to update it for the EJF retracts, and a built-up, plug-in wing to make transport easier. Again.. no time frame though..

Jul 25, 2002, 07:00 PM
EDF all the way!
bruff's Avatar

Foam wings

I used CNC Foam Factory for the cores. He has an ad here on Ezone.
Bob Ruff
Jul 25, 2002, 11:24 PM
Doug Cronkhite's Avatar
Just as an FYI.. this design may become a kit soon. I can't say where or when yet until I get some details worked out.. but it's VERY possible..

Jul 26, 2002, 10:31 AM
Registered User
byoung's Avatar

A possible kit is really good news.

Please keep us posted.

Jul 26, 2002, 10:53 AM
Real Men Fly Pink Planes...
kepople's Avatar
I'll take one!!!!

WhooHooo! What a good job. Glad to hear it flew well!

I dont have time to build anymore, but for that thing I will make time!

Jul 26, 2002, 01:08 PM
2018 EDF Jet Jam June 14-17
Robert Belluomini's Avatar

90 mm Fans

Originally posted by dcronkhite
Just as an FYI.. this design may become a kit soon. I can't say where or when yet until I get some details worked out.. but it's VERY possible..

Hi Doug,
I would imagine a kit for the 90mm fans would be a really hot set up.
I would buy one in a heartbeat
Thanks Bob